Short answer: The Zomacton label sets a weekly dose by body weight for children, split into equal doses 3, 6 or 7 days a week: 0.18 to 0.3 mg/kg/week for growth hormone deficiency, up to 0.375 for Turner syndrome, up to 0.37 for idiopathic short stature, 0.35 for SHOX deficiency and up to 0.47 for SGA. Adults inject daily, starting at about 0.2 mg/day or 0.006 mg/kg/day.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Zomacton is approved for: Zomacton is approved for children with growth failure from growth hormone deficiency, short stature with Turner syndrome, idiopathic short stature (height SDS of -2.25 or below), short stature or growth failure from SHOX deficiency, or short stature after being born small for gestational age with no catch-up growth by 2 to 4 years of age. It is also approved to replace growth hormone in adults with growth hormone deficiency (sections 1.1 and 1.2).
Source
ZOMACTON (somatropin) for injection, for subcutaneous use, prescribing information and Instructions for Use. Ferring Pharmaceuticals. DailyMed, version published August 28, 2026. DailyMed setid 85ba081b-bee0-4a9a-aa0f-ae5b5e9a0886
Zomacton is injected under the skin of the back of the upper arm, abdomen, buttock or thigh, rotating sites to avoid fat loss. It can be given with a standard sterile disposable syringe (section 2.1).
The 5 mg vial is mixed with 1 mL to 5 mL of the bacteriostatic sodium chloride diluent (with benzyl alcohol). The 10 mg vial is mixed with the 1 mL diluent syringe of bacteriostatic water (with metacresol). The vial is swirled, not shaken, and not used if cloudy (section 2.4).
Vials are stored in the refrigerator before and after mixing. A mixed 5 mg vial is used within 14 days and a mixed 10 mg vial within 28 days (section 16.2 and Instructions for Use).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Condition | Dose on the label |
|---|---|
| Pediatric GH deficiency | 0.18 mg/kg/week to 0.3 mg/kg/week (0.026 mg/kg/day to 0.043 mg/kg/day) |
| Turner syndrome | Up to 0.375 mg/kg/week (up to 0.054 mg/kg/day) |
| Idiopathic short stature | Up to 0.37 mg/kg/week (up to 0.053 mg/kg/day) |
| SHOX deficiency | 0.35 mg/kg/week (0.05 mg/kg/day) |
| Small for gestational age (SGA) | Up to 0.47 mg/kg/week (up to 0.067 mg/kg/day) |
| Adult GH deficiency, non-weight based | Start approximately 0.2 mg/day (range, 0.15 mg/day to 0.3 mg/day); increase every 1 to 2 months by approximately 0.1 mg/day to 0.2 mg/day |
| Adult GH deficiency, weight based | Start 0.006 mg/kg daily; increase to a maximum of 0.0125 mg/kg daily |
For children, the weekly dose is individualized by growth response and divided into equal doses given 3, 6 or 7 days per week.
SGA: in very short children (height SDS below -3) and older pubertal children, a larger starting dose (up to 0.067 mg/kg/day) is considered, with a gradual reduction if strong catch-up growth occurs. In children under 4 with height SDS between -2 and -3, a start at 0.033 mg/kg/day is considered.
If height velocity does not increase, especially in the first year, adherence and other causes such as hypothyroidism, undernutrition, advanced bone age and antibodies are checked. Zomacton for growth is stopped once the growth plates have fused.
Adult doses are given daily and adjusted by clinical response and IGF-1, and lowered for side effects or IGF-1 above the normal range. The weight-based regimen is not recommended for obese people, who are more likely to have side effects on it.
Older adults may start lower with smaller increases. Estrogen-replete women and people on oral estrogen may need higher doses. People treated as children whose growth plates have closed are re-evaluated before continuing as adults.
An eye exam is done before starting and periodically after, to check for optic nerve swelling.
If somatropin-induced intracranial hypertension is diagnosed, Zomacton can be restarted at a lower dose once the signs have resolved.
Women who are pregnant or planning pregnancy tell their healthcare provider, since they may need a different Zomacton formulation (the 5 mg diluent contains benzyl alcohol).
The Zomacton label gives no missed-dose instruction. Ask your prescriber or pharmacist what to do if a dose is missed.
In Dose Track you set up Zomacton as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.